congenital abnormalities Flashcards
agenesis
is the absence of one or both of the kidneys
hypoplasia
small kidneys but normal development
horseshoe kidney
fusion at either pole of the kidney, most commonly at the lower pole
duplex collecting system
one of the most common congenital renal tract abnormalities characterised by incomplete fusion of the upper and lower pole of moieties resulting in a variety of complete or incomplete duplications of the renal system
PKD infantile type
- autosomal recessively inherited
- associated with congenital hepatic fibrosis
benign renal tumours
- fibroma
- adenoma
- angiomyolipoma
- juxtaglomerular tumours
fibroma
benign tumour composed of fibrous tissue, medullary origin, white nodule
adenoma
- most common benign renal tumour
- arises in the cortex
- yellowish nodules which are less than 2cm in size
angiomyolipoma
- composed of fat, muscle and blood vessels, can be multiple and bilateral
- associated with tuberous sclerosis
juxtaglomerural tumours
secrete renin and cause secondary hypertension
urothelial carcinomas can occur
at the renal pelvis or calyces
renal cell carcinoma is the
most common malignant renal cancer
renal cell carcinoma is most common in whom
elderly males
renal cell carcinoma arises from
the epithelial cells of the proximal convoluted tubules (part of the nephron which is in the renal cortex)
the most common type of renal cell carcinoma
is composed of polygonal epithelial cells and are filled with clear cytoplasms full of carbohydrates and lips (lipids give the yellow colour)
renal cell carcinomas have been linked to
mutations on the short arm of chromosome 3, one of the main genes involved is the VHL gene which codes for pVHL
pVHL is
von hippel lingua tumour supressor protein
mutation in pVHL
allows the iGF-1 pathway to go into over-drive allowing dysregulated cell growth and up regulates specific transcription factors called hypoxia inducing factors which generated VEGF and VEGF receptors causing the formation of new blood vessels (angiogenesis) which allows tumours to form
renal cell carcinomas can occur
sporadically or as part of an inherited syndrome
sporadic renal cell carcinomas
- usually solitary in the upper pole of the kidney,
- more common in older males who smoke
inherited syndromes causing renal cell carcinomas
von hippel lindau syndrome which is caused by mutation of the VHL gene and causes CNS and retinal haemangioblastomas and renal cell carcinomas
symptoms of renal cell carcinoma
haematuria, palpable abdominal mass, pain in flank region
because renal cell carcinoma causes
chronic inflammation also causes fever and weight loss
renal cell carcinomas also classically cause
various paraneoplastic syndromes
paraneoplastic syndromes caused by renal cell carcinoma
- tumour can produce erytopoetin which can cause excessive production of red blood cells causing polycythaemia
- tumour can produce renin causing hypertension
- tumour can produce PTHrP causing hypercalcaemia
- tumour can produce ACTH causing cushings synrome
in rare cases
large renal cell carcinoma of the left kidney can block the left renal vein and impede normal venous drainage of the left kidney causing dilation of the left testiualr vein causing a hydrocele (since the right testicualr vein drains directly into the inferior vena can blockage of the right renal veins does not have the same affect)
renal cell carcinomas can invade
renal veins and spread into the inferior vena cava which can cause lung metastases and bone metastases
staging of renal cell carincom
T= size of tumour and whether it has spread to nearby areas N= whether the tumour has spread to retroperitoneal nodes M= degree of metastases
management of renal cell carcinomas
- surgical resection
- chemokines and antibodies
- molecular target therapy
transitional cell carcinoma
is the most common form of malignant cancer in the lower urinary tract
transitional cell carcinoma is more specifically known as
urothelial cell carcinoma
urothelial cell carcinoma can affect
anywhere form the pelvicalyceal system to the urethra but 90% arise from the urothelium of the bladder
urothelium is a specific type of
transitional cell epithelium that lines the inner surface of the majority of the urinary tract
the urothelium is composed of
3-7 layers and forms a tight barrier that holds urine which prevents toxins moving back into the body
barrier function of the urothelium is achieved by
the umbrella cells that line the luminal surface of the urothelium and are held together by high resitatnc tight junctions and are lined by a unique protein-lipid complex called a plaque
the cells of the transitional epithelium have
the ability to stretch with an expanding bladder
2 main forms of uroeithelial cell carcinmas
- mutations of the p53 gene (tumour suppressor protein) this allows urothelial cells to grow horizontally and some invade deeper bladder tissue
- independant of the p53 gene; papillary tumours grow outwards from the uroepithelium, they tend to be less aggressive as they tend not to invade deeper bladder tissues
commonest présentation of uurothelial cell carcinoma
painless haematuria
diagnosis of urothelial carcinoma
cystoscopy and biopsy
risk factors for urothelial carcinoma
- elderly
- carcinogens: Pee SAC
Phenacetin (banned analgesic)
Smoking
Aniline (dye and rubber)
Cyclophosphamide
75% of urothelial carcinomas arise
in the trigone of the bladder
treatment of urothelial carcinoma
- if tumour is localised and non-invasive then it may be able to be respected using trans-urethral resection which is followed by intra-vesical chemotherapy
- if the cancer is aggressive then the bladder and prostate gland may have to be removed (cysts-prostatectomy) followed by chemotherapy
other malignant tumours
- adenocarcinoma= seen in long standing cystitis cystica
- squamous carcinoma seen in recurrent calculi or schistosomiasis
- embryonal rhabdomyosarcoma= commonest malignant bladder tumour in children
nephroblastoma also known as
wilms tumour
wilms tumour
commonest intra-abdominal tumour in children
